As methods for manufacturing nano-fibers, drawing, template synthesis, phase separation, self assembly, and electro-spinning are known. Among these methods, the electro-spinning method is being generally applied to continuously manufacture nano-fiber.
In the electro-spinning method, a high voltage is applied between a nozzle spinning a spinning solution and a stage on which a substrate is disposed, forming an electric field larger than the surface tension of the spinning solution and thus allowing the spinning solution to be spun in a form of nano-fiber. Nano-fibers manufactured by the electro-spinning method are affected by the material properties such as viscosity, elasticity, conductivity, dielectric property, polarity, and surface tension of the spinning solution, the intensity of electric field, and the distance between a nozzle and an integrated electrode.
The method of forming a nano-fiber by electro-spinning is a well-known technology. Meanwhile, there are many attempts to arrange nano-fibers, formed as described above, in a desired direction. Representative examples thereof include a method of obtaining arranged nano-fibers by performing electro-spinning on electrodes formed adjacent to each other and a method of arranging nano-fibers at desired locations by maintaining a distance between a nozzle and a substrate at a very close location. However, these methods have limitations in terms of commercialization.